Fuel cells generate electric energy through electrochemical reaction between fuel gas and oxidizing gas. As fuel gas supplied to fuel cells, hydrogen gas is used which is obtained by steam reforming hydrocarbon-based raw fuel.
In the steam reforming process described above, an amount of water which corresponds to an amount of steam used for the reforming reaction needs to be supplied to a reformer. Although there are methods in which such water is supplied from outside, a method attracts people's attention in which water contained in exhaust gas generated as a result of electric power generation in fuel cells is circulated as water needed for the reforming process. In a fuel cell generation system using the latter method, condensate resulting from recovering water contained in exhaust gas from the fuel cells needs to be circulated after it has been refined to pure water and stored. Patent literatures 1 and 2 disclose apparatuses for reforming and purifying condensate to produce pure water.